NodeJS (后端)从POST调用中接收数据，那么如何在ReactJS (前端)中显示？

import React, { useState, useEffect } from 'react';

const MyComponent = () => {
  const [data, setData] = useState('');

  useEffect(() => {
    fetchData();
  }, []);

  const fetchData = async () => {
    const response = await fetch('/api/data', {
      method: 'POST',
      body: JSON.stringify({ key: 'value' }),
      headers: {
        'Content-Type': 'application/json'
      }
    });
    const result = await response.json();
    setData(result);
  };

  return (
    <div>
      <p>Data from NodeJS backend: {data}</p>
    </div>
  );
};

export default MyComponent;

const express = require('express');
const app = express();

app.use(express.json());

app.post('/api/data', (req, res) => {
  const receivedData = req.body;
  // 处理接收到的数据
  // ...

  const processedData = 'Processed data';
  res.json(processedData);
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});